Common Peroneal Nerve Palsy Secondary to a Proximal Tibiofibular Joint “Ganglion Cyst”—A Case Report and Review of Literature

Although ganglion cysts occur frequently, their presence in the lower extremities is rare and they seldom cause peripheral nerve compression. There are enumerable case reports of intraneural ganglion involvement with the common peroneal nerve and its branches, the sural nerve, and the posterior tibial nerve but extraneural ganglion sciatic and common peroneal nerve palsy cases are quite rare. Our case, a 26 years old female patient presented with right leg tingling and radiating pain followed up gradually with progressive right sided foot drop. MRI diagnosed the lesion as a ganglion cyst and the EMG/NCV confirmed the level of compression at the right fibular head. The patient was electively operated with standard lateral approach and the ganglion cyst engulfing the common peroneal nerve was excised. The cyst was traced to the base of its articular origin, excised and stalk ligated to prevent recurrence. At 1 year, there were no signs of recurrence and the patient was symptomatically free with no residual weakness. We, thus, report to you a rare cause of common peroneal nerve palsy—a proximal tibio-fibular joint “ganglion cyst”; a cause of foot drop which can be completely reversible if treated appropriately, its implications and thus, making its early diagnosis significant.